The present invention relates to a rotor and a motor.
A rotor of a motor may have a so-called Lundell-type construction using a permanent magnet field and including a pair of rotor cores and a field magnet (refer to, for example, Japanese Laid-Open Utility Model Publication No. 5-43749). Each of the two rotor cores includes a plurality of claw-poles arranged along a circumferential direction. The two rotor cores are joined with each other. The field magnet is arranged between the two rotor cores so that the claw-poles of the two rotor cores alternately function as different magnetic poles.
In the rotor described in Japanese Laid-Open Utility Model Publication No. 5-43749, a back magnet (auxiliary magnet in the document) is arranged between the back surface of the claw-poles (inner circumferential surface of flange in the document) and the field magnet to reduce leakage flux. Further, as shown in FIG. 3 of the document, the back magnet is annularly integrated, for example, to reduce the number of components.
In the rotor described above, the number of components is reduced by annularly integrating the back magnet. However, it is desirable that leakage flux be further suppressed.